A measuring device for the contactless detection of a rotational angle and/or torque on a stationary or rotating shaft is described in German Patent No. DE 29 51 148, in which two bodies, which are concentric to the shaft and are made of electrically conductive material, are provided, one of which is connected rotationally fixed to the shaft and the other of which is rotatable in relation thereto. A coil which is concentric to the shaft is situated in direct proximity to the two bodies and the bodies contain cutouts whose shared overlap area changes with increasing rotation angle occurring between the two bodies. In this measuring device, the fact is made use of that an alternating magnetic field originating from the coil generates stronger eddy currents in the two bodies the less the body adjacent to the coil is capable of shielding the second body in partial areas or in its entirety.
Measuring devices or sensor systems of this type, which are based on the generation of eddy currents, are frequently also designated as eddy current sensors.
A further eddy current sensor system is also described, for example, in German Patent Application No. DE 10 2005 025 870.